1. Field of the Invention
The invention is related to the field of fuel injector valves and in particular to a small size high speed electrically actuated fuel injector valve for internal combustion engines.
2. Description of the Prior Art
The current trend in internal combustion engine fuel control systems is to electronically compute the engine's fuel requirements and to provide to the engine the computed quantity of fuel through electrically actuated fuel injector valves. To date, the fuel injector valves still represent a limiting factor in the accuracy of the quantity of fuel being delivered. As a result, there is a concerted effort in the automotive industry to upgrade the performance capability of these fuel injector valves to improve their reliability and reduce their cost. Currently, most of the fuel injector valves used in the automotive industry are labor intensive requiring a relatively large number of machined parts having close tolerances and complex assembly and calibration procedures.
This problem was initially addressed in U.S. Pat. No. 4,552,311 which discloses a fuel injector valve specifically designed to reduce the number of machined parts. Subsequently, a miniature fuel injector valve design was disclosed in U.S. Pat. No. 4,643,359 which further reduced the number of parts which required precision machining, was easier to assemble, was easier to calibrate, and had superior high speed performance.
The present invention is a subminiature or pico fuel injector valve which is smaller than the miniature fuel injector valve disclosed in U.S. Pat. No. 4,643,359, has fewer parts requiring precision machining and has superior high speed performance characteristics.